Anti-peeping backlight module

Abstract

The present disclosure proposes an anti-peeping backlight module, comprising the following elements. A first light-emitting element is arranged on the upper side of a transparent substrate, and a light-emitting angle range of the first light-emitting element is greater than or equal to 30 degrees and less than or equal to 45 degrees. The second light-emitting element and the light guide plate are arranged on the lower side of the transparent substrate, and the second light-emitting element is arranged in the hole of the light guide plate. In the first mode, the luminous intensity of the first light-emitting element is the first intensity, and the luminous intensity of the second light-emitting element is the second intensity. In the second mode, the luminous intensity of the first light-emitting element is the third intensity, and the luminous intensity of the second light-emitting element is the fourth intensity, wherein the first intensity is less than the third intensity, and the second intensity is greater than the fourth intensity. In this way, the purpose of anti-peeping can be achieved.

Description

Technical Field

[0001] The present disclosure relates to an anti-peeping backlight module, and more particularly to a backlight module provided with two light-emitting elements. Background Art

[0002] In one application of display panels, privacy protection must be achieved. Such display panels can reduce the contrast between left and right viewing angles and have a relatively narrow viewing angle. In the prior art, a microstructure can be designed on the light guide plate, combined with a prism sheet with a reverse microstructure to achieve the privacy protection purpose. Summary of the Invention

[0003] The embodiments disclosed herein provide an anti-peep backlight module, comprising a transparent substrate, a first light-emitting element, a second light-emitting element and a light guide plate. The transparent substrate has an upper side and a lower side opposite to each other. The first light-emitting element is arranged on the upper side of the transparent substrate, and the light emission angle range of the first light-emitting element is greater than or equal to 30 degrees and less than or equal to 45 degrees. The second light-emitting element is arranged on the lower side of the transparent substrate. The light guide plate is arranged on the lower side of the transparent substrate, and the light guide plate has a plurality of holes, which correspond to the second light-emitting elements respectively, and the second light-emitting elements are respectively arranged in the corresponding holes. In the first mode, the luminous intensity of the first light-emitting element is the first intensity, and the luminous intensity of the second light-emitting element is the second intensity. In the second mode, the luminous intensity of the first light-emitting element is the third intensity, and the luminous intensity of the second light-emitting element is the fourth intensity, wherein the first intensity is less than the third intensity, and the second intensity is greater than the fourth intensity.

[0004] In some embodiments, the first light-emitting element has a first maximum luminous intensity, and the second light-emitting element has a second maximum luminous intensity. The first intensity is less than or equal to 5% of the first maximum luminous intensity, and the second intensity is 100% of the second maximum luminous intensity. The third intensity is 100% of the first maximum luminous intensity, and the fourth intensity is greater than or equal to 10% of the second maximum luminous intensity and less than or equal to 30% of the second maximum luminous intensity.

[0005] In some embodiments, the first light-emitting elements correspond to the second light-emitting elements respectively, and the projections of the first light-emitting elements on the transparent substrate at least partially overlap with the projections of the corresponding second light-emitting elements on the transparent substrate.

[0006] In some embodiments, the second light-emitting element has a height relative to the lower side of the transparent substrate, and the thickness of the light guide plate is greater than or equal to the height.

[0007] In some embodiments, a plurality of mesh dot structures are formed on the upper surface or the lower surface of the light guide plate.

[0008] In some embodiments, the privacy protection backlight module further includes a diffusion sheet, which is disposed on an upper side of the transparent substrate, and the first light-emitting element is disposed between the diffusion sheet and the transparent substrate.

[0009] In some embodiments, the anti-peeping backlight module further includes a shielding layer, which covers a portion of the upper surface of the first light-emitting element and the side of the first light-emitting element, so that the first light-emitting element emits light from the upper surface of the first light-emitting element but not from the side of the first light-emitting element.

[0010] In some embodiments, the second light-emitting element emits light from a bottom surface and a side surface of the second light-emitting element.

[0011] In some embodiments, the anti-peeping backlight module further includes a back plate, the inner side of the back plate faces the light guide plate, and a reflective material is disposed on the inner side of the back plate.

[0012] In some embodiments, a microstructure is provided on the inner side of the back plate, and a projection of the microstructure on the transparent substrate at least partially overlaps with a projection of the second light-emitting element on the transparent substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to make the above features and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings.

[0014] Figure 1 is a schematic diagram illustrating an anti-peeping backlight module according to an embodiment;

[0015] Figure 2 is a side view of a transparent substrate according to one embodiment;

[0016] Figure 3 is a light envelope diagram of a first light emitting unit according to one embodiment;

[0017] Figure 4 is a side view of a backlight module according to one embodiment;

[0018] Figure 5 is a schematic diagram illustrating a dot structure on a light guide plate according to an embodiment;

[0019] Figure 6 FIG. 1 is a side view of a backlight module according to an embodiment.

[0020] Description of reference numerals:

[0021] 100: Backlight module

[0022] 110: Optical film

[0023] 120:Transparent substrate

[0024] 120a: upper side

[0025] 120b: lower side

[0026] 130: Light guide plate

[0027] 130a: Upper surface

[0028] 130b: lower surface

[0029] 140: Hole

[0030] 210: first light emitting element

[0031] 210U: Upper surface

[0032] 210S: Side

[0033] 220: Second light emitting element

[0034] 220S: Side

[0035] 220B: bottom surface

[0036] 310: Light Packet Diagram

[0037] 410: Back panel

[0038] 410a: Inside

[0039] 420:Reflective material

[0040] t: thickness

[0041] h: height

[0042] 501~504: Direction

[0043] 510: Dot structure

[0044] 511: First line

[0045] 512: Second line

[0046] 513: third line

[0047] 514: fourth line

[0048] 610: Holes

[0049] 620:Reflective material DETAILED DESCRIPTION

[0050] The terms “first”, “second”, etc. used herein do not particularly refer to an order or sequence, but are only used to distinguish elements or operations described with the same technical terms.

[0051] Figure 1 FIG is a schematic diagram illustrating an anti-peeping backlight module according to an embodiment. Figure 1The backlight module 100 includes an optical film 110, a transparent substrate 120, and a light guide plate 130, wherein the transparent substrate 120 is disposed between the optical film 110 and the light guide plate 130. The optical film 110 can be a diffuser, a polarizer, or any other suitable optical film. The transparent substrate 120 can be made of, for example, glass, polyethylene terephthalate (PET), or other light-transmitting materials. Alternatively, the transparent substrate 120 can be made of a conductive material such as metal or ITO (Indium Tin Oxide).

[0052] Figure 2 FIG. 1 is a side view of a transparent substrate according to an embodiment. Figure 1 and Figure 2 , the transparent substrate 120 has an upper side 120a and a lower side 120b opposite to each other. From another perspective, the optical film 110 is disposed on the upper side 120a of the transparent substrate 120, and the light guide plate 130 is disposed on the lower side 120b of the transparent substrate 120. The upper side 120a of the transparent substrate 120 is provided with a first light-emitting element 210, and the lower side 120b is provided with a second light-emitting element 220. These light-emitting elements are, for example, light-emitting diodes. The size of these light-emitting diodes can be in the millimeter level, micrometer level, or nanometer level, but the present disclosure is not limited thereto. The first light-emitting element 210 and the second light-emitting element 220 are, for example, arranged in a matrix, each first light-emitting element 210 corresponds to one second light-emitting element 220, and the projection of each first light-emitting element 210 on the transparent substrate 120 at least partially overlaps with the projection of the corresponding second light-emitting element 220 on the transparent substrate 120. In other words, the first light-emitting element 210 and the second light-emitting element 220 are disposed on the upper and lower sides of the transparent substrate 120 opposite to each other.

[0053] In this embodiment, the light emitting angle range of the first light emitting element 210 is greater than or equal to 30 degrees and less than or equal to 45 degrees, so as to provide a light source with a narrow viewing angle. Figure 3310. In some embodiments, the backlight module further includes a shielding layer 230 for covering a portion of the upper surface 210U of the first light-emitting element 210 and the side surface 210S of the first light-emitting element 210, so that the first light-emitting element 210 emits light from the upper surface 210U but not from the side surface 210S. On the other hand, the second light-emitting element 220 has a lower surface 220B and a side surface 220S, and the second light-emitting element 220 emits light from both the lower surface 220B and the side surface 220S. In some embodiments, the first light-emitting element 210 and the second light-emitting element 220 are in the shape of a cube, so each light-emitting element has four sides, and the shielding layer 230 can cover the four sides of the first light-emitting element 210. However, the present disclosure does not limit the shape of the light-emitting element. In some embodiments, the shielding layer 230 can also be omitted.

[0054] The light guide plate 130 is provided with a plurality of holes 140, and these holes 140 correspond to the second light emitting elements 220. After the transparent substrate 120 and the light guide plate 130 are combined, these second light emitting elements 220 are respectively disposed in the holes 140. For example, Figure 4FIG1 is a side view of a backlight module according to one embodiment. The backlight module includes a backplate 410 having an inner side 410a, a light guide plate 130 disposed on the inner side 410a of the backplate 410, a transparent substrate 120 disposed on the light guide plate 130, and one or more optical films 110 disposed on the transparent substrate 120. In other words, the first light-emitting element 210 is disposed between the optical film 110 and the transparent substrate 120. The light emitted by the first light-emitting element 210 is emitted through the optical film 110. The light emitted by the second light-emitting element 220 is emitted from the lower surface 220B and the side surface 220S. A reflective material 420 is disposed on the inner side 410a of the backplate 410 to reflect the light. The light is diffused upward through the light guide plate 130 to provide a light source with a wide viewing angle. In some embodiments, the reflective material 420 may also have microstructures to evenly scatter light. The projection of these microstructures on the transparent substrate 120 at least partially overlaps with the projection of the corresponding second light-emitting element 220 on the transparent substrate 120. In some embodiments, the reflective material 420 may correspond to multiple second light-emitting elements 220. The backlight module 100 can operate in two modes. The first mode, also known as the normal mode, provides a wide-angle light source. In this mode, the first light-emitting element 210 has a low luminous intensity (a first intensity), while the second light-emitting element 220 has a high luminous intensity (a second intensity). The second mode, also known as the privacy mode, provides a narrow-angle light source. In this mode, the first light-emitting element 210 has a high luminous intensity (a third intensity), while the second light-emitting element 220 has a low luminous intensity (a fourth intensity). It is worth noting that the above descriptions of "larger" and "smaller" refer to the first light-emitting element 210 / second light-emitting element 220 compared to themselves, rather than the first light-emitting element 210 compared to the second light-emitting element 220. In other words, the first strength is smaller than the third strength, and the second strength is larger than the fourth strength. However, the present disclosure does not limit the magnitude relationship between the first strength and the second strength, nor does it limit the magnitude relationship between the third strength and the fourth strength.

[0055] In some embodiments, the first through fourth intensities are expressed as percentages of the maximum luminous intensity of the corresponding light-emitting element. Specifically, the first light-emitting element 210 has a first maximum luminous intensity, which is less than or equal to 5% of the first maximum luminous intensity, and the third intensity is 100% of the first maximum luminous intensity. On the other hand, the second light-emitting element 220 has a second maximum luminous intensity, which is 100% of the second maximum luminous intensity, and the fourth intensity is greater than or equal to 10% and less than or equal to 30% of the second maximum luminous intensity. In another aspect, in normal mode, the first light-emitting element 210 emits at 5% of the first maximum luminous intensity (in some embodiments, the first light-emitting element 210 may also be turned off), while the second light-emitting element 220 emits at the second maximum luminous intensity. In anti-peep mode, the first light-emitting element 210 emits at the first maximum luminous intensity, and the second light-emitting element 220 emits at 10% to 30% of the second maximum luminous intensity. Since the first light-emitting element 210 primarily provides the light source in anti-peep mode, a narrow viewing angle can be achieved. In this case, the second light-emitting element 220 compensates for dark areas where there is no light source.

[0056] In some embodiments, the second light emitting element 220 has a height of t micrometers relative to the lower side of the transparent substrate 120 , and the light guide plate 130 has a thickness of h micrometers, where t and h are real numbers, and the thickness h is greater than or equal to the height t.

[0057] In some embodiments, the light guide plate 130 has an upper surface 130a and a lower surface 130b opposite to each other, and a plurality of dot structures are formed near the hole 140 on the upper surface 130a or the lower surface 130b. For example, Figure 5 This is a schematic diagram illustrating a dot structure on a light guide plate according to an embodiment. Figure 5 , Figure 5The dot structure 510 around two holes 140 is shown. On the upper surface 130a (or lower surface 130b), there are four directions 501-504 from the center of the hole 140 outward. The dot structure 510 is arranged in these four directions 501-504 and arranged in multiple rows along the corresponding directions. The dot structure 510 is a structure protruding from the upper surface 130 and can be completed through processes such as injection molding or roll molding. The dot structure 510 near the hole 140 is arranged more sparsely, while the dot structure 510 away from the hole 140 is arranged more densely. For example, below the left hole 140, the dot structure 510 is arranged in a first row 511, a second row 512, a third row 513, and a fourth row 514. The spacing between the dot structures 510 in the second row 512 is smaller than that in the first row 511, and the length of the second row 512 is longer than that of the first row 511. Similarly, the spacing between the dot structures 510 in the third row 513 is smaller than that in the second row 512, and the length of the third row 513 is longer than that of the second row 512. The spacing between the dot structures 510 in the fourth row 514 is smaller than that in the third row 513, and the length of the fourth row 514 is longer than that of the third row 513. In other words, along the path from one hole 140 to another, the dot structures 510 are initially arranged at a larger spacing, then the spacing gradually decreases (reaching the middle between the two holes 140), and then the spacing gradually increases again. These dot structures 510 are used to diffuse light along directions 501-504.

[0058] Figure 6 FIG is a side view of a backlight module according to an embodiment. Figure 6 In this embodiment, the hole 610 in the light guide plate 130 does not penetrate the light guide plate 130, but is recessed from the upper surface 130a, and the second light-emitting element 220 is disposed within the hole 610. Meanwhile, a reflective material 620 is disposed on the inner side 410a of the back plate 410. This reflective material 620 spans across multiple second light-emitting elements 220, meaning that the projection of the reflective material 620 on the transparent substrate 120 includes the projections of all second light-emitting elements 220 on the transparent substrate 120. In some embodiments, the upper surface of the reflective material 620 may also have microstructures.

[0059] Although the present invention has been disclosed above with reference to the embodiments, they are not intended to limit the present invention. Anyone with ordinary knowledge in the technical field may make slight changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the appended claims.

Claims

1. A privacy protection backlight module, characterized in that: include: a transparent substrate having an upper side and a lower side opposite to each other; A plurality of first light-emitting elements are disposed on the upper side of the transparent substrate, wherein the light emission angle range of the plurality of first light-emitting elements is greater than or equal to 30 degrees and less than or equal to 45 degrees; a plurality of second light-emitting elements, disposed on the lower side of the transparent substrate; as well as A light guide plate is disposed on the lower side of the transparent substrate, the light guide plate having a plurality of holes, the plurality of holes respectively corresponding to the plurality of second light emitting elements, and the plurality of second light emitting elements are respectively disposed in the corresponding holes. In the first mode, the luminous intensity of the plurality of first light-emitting elements is a first intensity, and the luminous intensity of the plurality of second light-emitting elements is a second intensity. In the second mode, the luminous intensity of the plurality of first light-emitting elements is a third intensity, and the luminous intensity of the plurality of second light-emitting elements is a fourth intensity, wherein the first intensity is less than the third intensity, and the second intensity is greater than the fourth intensity.

2. The privacy protection backlight module according to claim 1, wherein: wherein the plurality of first light-emitting elements have a first maximum light-emitting intensity, the plurality of second light-emitting elements have a second maximum light-emitting intensity, the first intensity is less than or equal to 5% of the first maximum light-emitting intensity, and the second intensity is 100% of the second maximum light-emitting intensity, The third intensity is 100% of the first maximum luminous intensity, and the fourth intensity is greater than or equal to 10% of the second maximum luminous intensity and less than or equal to 30% of the second maximum luminous intensity.

3. The privacy protection backlight module according to claim 1, wherein: The plurality of first light-emitting elements respectively correspond to the plurality of second light-emitting elements, and projections of the plurality of first light-emitting elements on the transparent substrate at least partially overlap with projections of corresponding second light-emitting elements on the transparent substrate.

4. The privacy protection backlight module according to claim 1, wherein: The second light emitting element has a height relative to the lower side of the transparent substrate, and the thickness of the light guide plate is greater than or equal to the height.

5. The privacy protection backlight module according to claim 1, wherein: The upper surface or the lower surface of the light guide plate has a plurality of lattice structures.

6. The privacy protection backlight module according to claim 1, wherein: The system further includes a diffusion sheet, which is disposed on the upper side of the transparent substrate, and the plurality of first light-emitting elements are disposed between the diffusion sheet and the transparent substrate.

7. The privacy protection backlight module according to claim 1, wherein: It also includes a shielding layer, which covers a portion of the upper surface of the first light-emitting element and the side of the first light-emitting element, so that the first light-emitting element emits light from the upper surface of the first light-emitting element but not from the side of the first light-emitting element.

8. The privacy protection backlight module according to claim 7, wherein: The second light emitting element emits light from the bottom surface and the side surface of the second light emitting element.

9. The privacy protection backlight module according to claim 1, wherein: Also includes: A back plate, the inner side of the back plate faces the light guide plate, and the inner side of the back plate is provided with a reflective material.

10. The privacy protection backlight module according to claim 9, wherein: The reflective material has a microstructure, and a projection of the microstructure on the transparent substrate at least partially overlaps with a projection of one of the plurality of second light-emitting elements on the transparent substrate.

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